Polymer-based three-waveguide polarization beam splitter with reducing crosstalk for optical circuitry

Polarization beam splitters are pivotal in manipulating polarized light within photonic integrated circuits for various optical applications. This study introduces a single-mode polarization beam splitter composed of three waveguides realized with polymer materials. The device optimization process employed beam propagation method, explicitly using the RSoft CAD BeamProp solver. Our proposed beam splitter performs exceptionally with 99 % complete and null light transmission efficiency. In particular, it demonstrates minimal insertion loss (0.04 dB for complete transmission and 0.07 dB for null transmission) and low coupling loss (0.03 dB and 0.04 dB for complete transmission, 21.9 dB and 36.3 dB for null transmission from input to bridge and bridge to output waveguides, respectively). Additionally, the beam splitter showcases significantly reduced crosstalk: -27 dB and -26.98 dB for TE modes during complete light transfer, and -36.28 dB and -33.61 dB for TM modes during null light transfer. These results underscore its potential for advancing integrated optical systems.